In one of the harshest criticisms yet of the war and the causes behind it, Blix labeled the coalition as medieval witch-hunters, and said intelligence about Baghdad's weapons programme had been "over-interpreted."
"In the Middle Ages when people were convinced there were witches, they certainly found them. This is a bit risky," Blix said.
Blix said a pre-war British dossier on Iraqi weapons "lead the reader to the conclusions that are a little further reaching" than was the case.
"What in a way stands accused is the culture of spin, the culture of hyping…advertisers will advertise a refrigerator in terms that we don’t quite believe in, but we expect governments to be more serious and have more credibility," Blix said.
"What in a way stands accused is the culture of spin, the culture of hyping"
Ex-UN Chief Weapons Inspector
His trenchant criticism came just a day after the former chief weapons' inspector claimed that Iraq must have had got rid of its deadly weapons arsenal 10 years ago.
But Blix's latest attack is certain to add to the embarrassments of the US and UK governments.
Both are under fire for having failed to unearth any weapons of mass destruction in Iraq, despite touting their existence as the main justification for going to war.
Instead, they now say the search will take time and that evidence will eventually be uncovered.
"The patience that they require for themselves now was not anything that they wanted to give to us," said Blix, whose inspectors were forced to pull out of Iraq in March, since the coalition was in undue haste to go to war.
Blix also said that a few "minor things" which his teams had uncovered in Iraq were more likely to have been "debris from the past" than "tips of the iceberg" of an existing weapons programme.